This came about as a thought experiment as I was working on some things for my weekly game but I have to ask "How many and what kinds of die would you use to calculate the damage of a nuclear/atomic bomb blast"?

So funny! I remember the original Gamma World had die-results for "clean" and "dirty" fission bombs. Pretty sure they did 40d10 and 70d10 or something equally weak, arbitrary and outrageously bizarre. So much fun. Sigh.

Don't forget the accompanying blinding of the blast, flying object damage, electromagnetic pulse (might shut down electrical constructs) and everybody's favorite endlessly debilitating radiation sickness that causes hair and teeth to fall out and body generally to crap out. Again, SO much fun. Makes being a zombie start to look like an advantage, though eating rad-victims brains may not be so cool.

I am running a d20-esque superhero game and here are the guidelines I'll be using when/if the heroes run afoul of nukes:
A 1 megaton blast will do 256d6 heat and 16d6 sonic damage to a range of 5 km. (if you are interested the reflex save DC is 256). each doubling of the yield doubles the heat and sonic damage as well as the range increment.
Each range increment away, the damage halves as well as the save DC.
Each halving of the range increment would double the damage for ?? (maybe 3 or 4 iterations ?)
This system does break down below 4 kilotons* and above 10 megatons**. The above range increment is for an air burst. If it is an underground blast, I would drop the range increment by an order of magnitude.

this is what I was keeping in mind when coming up with these rules:
- a bush fire is CR6 and does 6d6 heat damage a round (real world, the heat output is about 100 kiloWatts per square metre)
- 3rd degree burns are life threatening, 2d6 to 3d6 heat damage is life threatening to a mortal
- the tsar bomba (go wikipedia yay!) was a 50 MT yield that was able to cause 3rd degree burns at a range of 100 km
- a 1 metre thick wall of super duper bank vault reinforced concrete will stop the first 1600 hp of damage.

* - if you could get a relatively clean tactical nuke at 4 kilotons, I'd say the damage would be 1d6 heat and 1 pt of sonic at 800 metres, 2d6 heat at 400 metres, 4d6 heat damage at 200 metres, 8d6 at 100 metres and 16d6 at 50 metres
** - at a guess I would give a 10 megaton blast the following stats: 1000d6 heat (per round for 30 combat rounds), 150d6 sonic(once, travelling at 1 km/3 seconds), 7 kilometre range increment, so at 70 km away you would take 1d6 heat

I guess the big question is...do you have enough dice..just getting a tub full of hundreds of dice and throwing them on the table is enough to chill the bones of anyone. would love to see the expressions on the players faces when it happens. Love it! :))

Results here!
Comes out to a grand whopping total of 1,058,600 heat damage over 30 rounds!
Sorry for the huge post, I was unable to put a spoiler inside a spoiler and didn't know how else to hide the data.

So the real question, if you gained immunity to fire, could you conceivably survive the 500ish odd sonic damage?

How much damage it deals should depend on how survivable you want it to be.

In the real world, damage from a nuke kills any of we mortal first-level commoners. But there's no precedent in reality for what happens if you drop a nuke on a 20th-level raging barbarian. What spells instant death for humans may not automatically kill the superhumans PCs become at higher levels. Considering how many superheroes in comics seem able to withstand nuclear radiation, I don't think it's unreasonable to make the damage low enough that high-level characters would probably survive it.

And obviously, all damage dealt by a nuke is reduced to 0 against targets inside a fridge. That's just common sense.

According to GURPS Vehicles 3rd ed a 1KT nuke inflicts 12d6 x 200,000 in a 128 yards radius ; this is only the explosive damage (about 30% of that is flash and rads, and another 30% is added heat damage).

A 1 MT nuke inflicts 12d6 x 2000,000,000 in a 1024 yards radius.

edit: that is only the damage in the first radius increment.For every other increment quarter damage; in the case of 1 KT the dam are divided by 4 for every other 128 yards radius.

How much damage it deals should depend on how survivable you want it to be.

In the real world, damage from a nuke kills any of we mortal first-level commoners. But there's no precedent in reality for what happens if you drop a nuke on a 20th-level raging barbarian. What spells instant death for humans may not automatically kill the superhumans PCs become at higher levels. Considering how many superheroes in comics seem able to withstand nuclear radiation, I don't think it's unreasonable to make the damage low enough that high-level characters would probably survive it.

And obviously, all damage dealt by a nuke is reduced to 0 against targets inside a fridge. That's just common sense.

The bomb dropped on Nagasaki inflicted much less damage than the one of Hiroshima due to hilly terrain.

One should take in account a lot of factors before reading the damage, otherwise just say "you are dead,everything in a 40 kilometers radius is gone".
And NO, you cannot survive a nuclear explosion by closing yourself inside a fridge

Radiation (Ex): The area within a quarter-mile of a nuclear toxyderm is considered highly irradiated (see Radiation Sickness, below), so characters receive a low exposure to radiation if they remain in the area for less than a minute and a moderate exposure if they stay longer. If the nuclear toxyderm hits a creature with a slam attack, that creature receives a severe exposure to radiation.

Breath Weapon (Ex): The nuclear toxyderm's breath weapon is a 100-foot cone of white-hot nuclear slag and fullspectrum radiation. It deals 20d6 points of damage to all in its path, or half damage if a Reflex save succeeds (DC 10 + 1/2 toxyderm's Hit Dice + toxyderm's Constitution modifier). Any creature that takes damage from the cone also suffers a high exposure to radiation (see the Radiation Sickness).

Chain Reaction (Su): If the nuclear toxyderm is reduced to 0 or fewer hit points, it explodes in a blinding flash of light that deals 400 points of damage to everything (creatures and objects alike) within 400 feet and 100 points of damage to everything within a mile; a successful Reflex save halves the damage (DC 10 + 1/2 toxyderm's Hit Dice + toxyderm's Dexterity modifier). This explosion generally results in a milehigh mushroom cloud and a highly radioactive crater a quarter-mile across.

This came about as a thought experiment as I was working on some things for my weekly game but I have to ask "How many and what kinds of die would you use to calculate the damage of a nuclear/atomic bomb blast"?

On Nukes:
One guy in Japan who died fairly recently actually survived BOTH Hiroshima and Nagasaki, being injured by both bombs. A little google-fu will pull up his story.
Most nukes, with even modest prepared shelters, are a lot more survivable than the popular imagination imagines. There's plenty of declassified information regarding this available, once again with a bit of google-fu.
From a game perspective, think of nukes as being like the nastiest ritual magic blasting that the highest level casters in the world have available to them. The power should be roughly comparable. I do the same for the various divinations---equating them to Electronic intelligence, and considering the highest level casters in the campaign as being comparable to the NSA or equivalent agencies. Would a direct hit from such a ritual magic cast kill a given PC? That's the question to ask, moreso that just the desire to throw a gaming store's stockpile of dice.

If I were to do just the damage, I would probably take a simple approach. Like 500 damage (fort 30 half) and structures, vehicles, and unattened objects take ten times the amount. This way that, in most situations, any animal (like a T-rex) would get killed even if they made the fortitude save, and only the very powerful monsters and players could have a decent shot of surviving.

Edit: That would make a funny capstone ability for the Alchemist. Making a super alchemy bomb once a year that you can have only one at a time.

Apparently, there was a 7% survival rate for those within 0-1000' of the point directly below the detonation of the Hiroshima bomb. Of course, the bomb was detonated about 580 m (1900 feet) in the air, so no one was extremely close to the detonation, and Little Boy had a yield equal to "only" 13 kilotons of TNT.

So, a small A-bomb should be survivable by very lucky normal people at a range of 1900 feet. I'd expect that at, say, 30' the damage would be unsurvivable for any character.

Nice to hear everybody chiming in on this with a nice chunk actual statting as well as craziness. That being said I want to address this...

Lemmy wrote:

Astral Wanderer wrote:

They didn't all escape it undamaged and many of them suffered a literal Hell due to radiations afterwards, but they survived.

Wait, so there were actual demons there? With horns and tridents and stuff?

I knew nuclear bombs were powerful, but I never thought they involved black magic... You learn something everyday, huh?

Or do you mean they could only read really crappy books afterwards?

You know I didn't think about it before but in pathfinder I would totally have that happen next, I mean your talking about one hell of a loss of life and an explosion powerful enough to probably knock a hole into another plane. Will say though I think it would be more daemons then demons or devils. God that would be horrifying, could you imagine making that reflex save, living through that insanity, and then you see a small horde of daemons starting to peel out of the puncture holes in reality that this bomb has made?

Isn't "emotionless" one of the possible interpretations of the word "serious"? May not be dictionary-accurate, though.

doc the grey wrote:

Nice to hear everybody chiming in on this with a nice chunk actual statting as well as craziness. That being said I want to address this...

Lemmy wrote:

Astral Wanderer wrote:

They didn't all escape it undamaged and many of them suffered a literal Hell due to radiations afterwards, but they survived.

Wait, so there were actual demons there? With horns and tridents and stuff?

I knew nuclear bombs were powerful, but I never thought they involved black magic... You learn something everyday, huh?

Or do you mean they could only read really crappy books afterwards?

You know I didn't think about it before but in pathfinder I would totally have that happen next, I mean your talking about one hell of a loss of life and an explosion powerful enough to probably knock a hole into another plane. Will say though I think it would be more daemons then demons or devils. God that would be horrifying, could you imagine making that reflex save, living through that insanity, and then you see a small horde of daemons starting to peel out of the puncture holes in reality that this bomb has made?

This came about as a thought experiment as I was working on some things for my weekly game but I have to ask "How many and what kinds of die would you use to calculate the damage of a nuclear/atomic bomb blast"?

How many sticks of Dynamite is it? 6d6 per stick of Dynamite and a 1 KTON Nuke was 3 sticks per pound x 2240 pounds x 1000 tons x 6 dice per stick = 40320000d6.

So the damage range for our One Kiloton Nuke is (40,320,000 hp - 231,920,000 hp). Remember though - a nuke isn't a one off damage it is continuous damage from radiation after the fact.

This came about as a thought experiment as I was working on some things for my weekly game but I have to ask "How many and what kinds of die would you use to calculate the damage of a nuclear/atomic bomb blast"?

How many sticks of Dynamite is it? 6d6 per stick of Dynamite and a 1 KTON Nuke was 3 sticks per pound x 2240 pounds x 1000 tons x 6 dice per stick = 40320000d6.

So the damage range for our One Kiloton Nuke is (40,320,000 hp - 231,920,000 hp). Remember though - a nuke isn't a one off damage it is continuous damage from radiation after the fact.

You know I didn't think about it before but in pathfinder I would totally have that happen next, I mean your talking about one hell of a loss of life and an explosion powerful enough to probably knock a hole into another plane. Will say though I think it would be more daemons then demons or devils. God that would be horrifying, could you imagine making that reflex save, living through that insanity, and then you see a small horde of daemons starting to peel out of the puncture holes in reality that this bomb has made?

Oh yeah, I like that idea since I read Lukyanenko's Watch pentalogy (Nochnoi Dozor and the sequels - oh and yes, the books are WAY better than the movies).

If you don't know what I'm talking about: in that world, you got the material plane and several "levels" of the "twilight" on top of that (think of several layers of an astral/shadow plane) - it takes magic to access the first, and each layer requires geometrically more power to enter and remain in it. A nuclear blast ruptures ruptures through all of them.

For good measure, add a bunch of dispel magic effect vs every active spell or magic item in the area of effect, because the raw energy literally blasts away the magic.

Oh, and btw... I think nuclear blasts are things which should make you think about implementing other types of subsystems for handling explosion damage. Like the one Shadowrun uses: every explosion has a base damage which is reduced by a certain amount per range increment between you and the center of the explosion.
In a smaller scale or for magical effects (like a fireball), the normal rules are fast and easy, but it just makes no sense that a subject touching the bomb takes just as much damage as a subject that's 5 ft in the max range.

Nuclear explosions are one of those "no save, instant death" situations.

The heat of the explosion is insanely hot, running all the way up into the 10s of millions of degrees. For comparison, the center of our Sun is roughly 27 million degrees.

You also have to contend with the force of the blast itself, which hits in 3 phases: the initial shockwave, which weakens any structures that it hits, and the blast winds which knock them down. After the sudden expulsion of all air pressure, you then have to deal with the sudden vacuum created by the explosion, which causes air to come rushing back towards the explosion, hitting you a third time. Your eardrums, being much less weaker than even a wooden board, aren't going to survive unless you're a great deal away from the explosion.

After the heat and the force of the explosion, hemorrhaging and air embolisms in your lungs and abdominal cavity as a whole, and the initial blast of the explosion, which has the capacity to instantly blind whoever is looking at it, you also have to deal with the effects of the radiation.

Going by what's available in Pathfinder so far, you could become immune to fire damage, be able to persist in any environment, and able to live without breathing. I'm not sure if you can gain a resistance or immunity to sonic damage, but that really doesn't matter.

If you can somehow survive the heat of the explosion and the lack of oxygen, the force of the blast itself would kill you, or if you were somehow able to reduce the force damage (unlikely), the force of the blast would bull rush you so hard you'd go flying, possibly into another structure (in which case you'd take a huge amount of "falling" damage) or your body would skip across the ground like a rock, shattering your body. And even if you somehow survived that (I suppose with Feather Fall or something), there's no way for you to resist the effects of the radiation, which is even worse; you wouldn't die quickly, you'd die slowly as the radiation deteriorated your body.

Pathfinder is ill-equipped to handle a weapon that is centuries more advanced than it.